The Chief Design Engineer for Colonial Warning Systems Wants to Know

question 28

Multiple Choice

The chief design engineer for Colonial Warning Systems wants to know the reliability of a two-lamp device intended to warn the operator of potential problems with a commercial steam kettle.One (either) lamp is to be lit if steam pressure drops below the desired level,and two (both) are to be lit if temperature drops below a desired level.His supplier estimates that a lamp has a failure rate of .2 per hour of operation,and a mean wear-out time of seven years with a standard deviation of eight months.What is the probability that a lamp will last at least until the expiration of the warranty,which is six years?

• A).9772
• B).9332
• C).8664
• D).8413
• E).4332

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Definitions:

Summary Statistics

Refers to a set of descriptive indices that summarize the central tendency, dispersion, and shape of a dataset distribution, including measures such as mean, median, variance, and standard deviation.

T-Test

A statistical test used to compare the means of two groups to see if they are significantly different from each other.

Sample SD

The standard deviation of a sample, a measure of the dispersion or variability of data points within the sample.

Population Mean

The average value of a set of characteristics for the entire population.